Boring-machine



E. A. DE FOREST.

BORING MACHINE. APPLICATION FILED MAR. 26. 1917.

Patented Apr. 20, 1920.

3 SHEETS-SHEET I.

r 0m f.. v e m 65 t v Wm H E. A. DE FOREST.

BORING MACHINE.

ARPLIQATION FILED MAR. 26. 1917.

Patented Apr. 20, 1920.

3 SHEETSSHEET 2.

E. A. DE FOREST.

BORING MACHINE.

APPLICATION man MAR. 26. m1.

1,337,393, Patented Apr. 20, 1920.

UNITED STATES PATENT OFFICE.

EDGAR A. DE FOREST, 0F MINNEAPOLIS, MINNESOTA, ASSIGNOR TO MARVEL MACHINERY COMPANY, OF MINNEAPOLIS, MINNEfSOTA.

BORING-MACHINE.

Application filed March 26, 1917.

I1 '0 aZZ whom. it may concern.-

Be it known that I, EDGAR A. DE Fonnsr, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Boring- Machines, of which the following is a specification.

My invention relates to boring machines, and has for its object to provide novel means for driving and controlling the boring bar of such machines. It is an especial object of my invention to provide balanced v and symmetrical driving means which may conveniently be electrically driven for oprating the boring bar, such driving means consisting of pairs of electric motors connected by differential gearing to a gear fast on a boring bar, two sets of said motors and driving devices being arranged on opposite sides of the boring bar so as to operate with a balanced drive thereupon. I also provide a novel and highly efiicient means for feeding the boring bar as the same is driven or rotated.

The full objects and advantages of my invention will appear in connection with the detailed description thereof, and are particularly pointed out in the claims.

In the drawings illustrating the application of my invention, in one form,

Figure 1 is a side elevation thereof. Fig. 2 is a top plan view of the same. Fig. 3 is a section on line 33 of Fig. 1. Fig. 4 is a fragmentary side elevation, partly in section, on line 4-4 of Fig. 3.

As illustrated, a frame casting comprising a base member 10 having upwardly extended web portions 11, 12, 13, is connected with a table or stand 15 to which is bolted a table 16. Table 16 is provided with tool receptacles 17 and 18 on each side thereof, and a rib 19 at the center of its upper surface 20. Matching into the rib 19 is an upper base member 21 which is secured by bolts 22 to the table 16. Base member 21 has thereon a standard 23 terminating in a tubular hearing member 24L from which extends a second standard 25 forwardly extended and provided with asupporting plate 26 in the vertical plane of a supporting plate 27 extending upwardly from the member 21 and in the plane of a similar plate 28 on the standard 11. A face plate 29 is bolted to plates "Specification of Letters Patent.

Serial No. 157,334.

26, 27, and 28. The face plate 29 has therein an enlarged aperture through which the boring bar 31 extends, as clearly shown in Figs. 1 and 2. A stand 32 is mounted for vertical movement on face plate 29, being controlled by a threaded spindle 33 and hand wheel 3 1. On the table portion 35 of stand 32 is a worl c-receiving table 36 controlled by an adjusting wheel 37. The above named parts are or may be, well known portions of a boring machine.

The boring bar 31 extends through a rotary sleeve 38 which is journaled in bearing 2%- and held therein by collars 39 and 40 fast on the sleeve, and also extends through hearing posts and $6 on either side of casings 42 and 13, respectively, extending upwardly from member 1a. The sleeve 38 passes rearwardly through a casing formed by a pair of symmetrical side members 12 and bolted together by central flanges and bolted to a stand 14; formed in conjunction with upper base member 21. The boring bar 31 has a rearward threaded extension e7 threaded through a sleeve 48 journaled in a bearin 49 fast on a standard 50 connected with top base member 21. The sleeve 48 at one end has a collar 48 and at the other has thereon a pair of gears 51 and 52 of different sizes adapted to be driven by complemental gears 53 and 5-1 on a sleeve splined on a shaft 55 and controlled by a shifter member 56 having a lever 5"? cooperating with a notched catch 58 either for holding both gears inoperative or either in mesh with its corresponding gear 51 or Extending outwardly from the stands 15 and i6 are supports 59 and 61 on one side and supports 62 and 63 on the other side. On the supports 59 and 61 are set a pair of electric motors 6 and 65. Motor 65 is fast on a sleeve 66 journaled upon a shaft 67 which extends through both motor casings 6 1 and 65; motor 64 is similarly fast on a sleeve 68 journaled on said shaft 67. The sleeve 66 is integrally connected with a bevel gear 69 and the sleeve 68 is similarly connected with a bevel gear 70 journaled respectively on shaft 6'? on opposite sides of a central spider 71 to which the bevel gears are connected by means of a group of bevel pinions 72 j ournaled upon arms of the spider 71 and meshing with both bevel gears 69 and 70. The spider 71 carries a spur gear 73 which meshes-with a spur gear 7 4 fast on sleeve 38.

Electric motors 82 and 83 are similarly connected with sleeves j ournaled on a shaft which is connected, by bevel gears 76, spider 77, pinions 78 thereon meshing with bevel gears 76 and a spur gear 7 9 with the spur gear 74 on sleeve 38. The gearsTB and 7 9 mesh with the gear 74 at diametrically opposite points in a horizontal plane. 1t will thus be seen that when electric power is turned into the motors 64, 65, 82, and 83 the drive gears 73 and '79 will be differentially operated to apply power through drive pinion 7 4 to the sleeve 38 and the boring bar 31 thereon so that the full power of each pair of motors will be utilized and uniformly applied to the driving of the boring bar shaft.

Referring to Fig. 3, it will be noted that a spur gear '80 partly housed in the casing formed by members 42 and'43 and partly housed in the stand 44 is fast on shaft 55 and meshes with gear 74 on sleeve 38. By this means, the shaft 55 is rotated and through either gear 53 meshing with gear 51 or gear 54 meshing with gear 52 drives the sleeve 48 threaded on shaft 47. Under these conditions the sleeve 48 will be driven in the same direction as sleeve 38. When the gear 53 meshes with gear 51 as shown in Fig. 1 the sleeve 48 will be driven faster than sleeve 38 which will result in retraction of the boring bar. When gear 54 meshes with gear 52' the sleeve 48 will be driven slower than sleeve 38, with the result that the boring bar will feed forward by reason of relative rotation of threaded shaft 47 in sleeve 48. When gears 54 and 53 are in neutral position so that the sleeve 48 is not driven said sleeve may be held stationary by means of a set screw 81 extending into the bearing 49, under which conditions the boring bar will be fed forward at maximum speed. Under such conditions also, the boring bar may be adjusted forward or back by hand throughthe operation of a hand wheel 82.

The advantages of my invention will be apparent. In such machinery as boring machines or lathes where a member is to be rotated with, considerable rapidity and is subject to great side strain because the load is applied at a point away from the axial center of the rotated member, it is particularly desirable to have the member driven from both sides so that the power will be applied uniformlyand the operation of the tool will be less subjectto vibration and consequently do more effective work. This result is accomplished in my present invention by the driving engagement of two gears at diametricallyopposite points. For convenience these gears are placed to drive in a horizontal plane, which gives a peculiarly effective structure by reason of the fact that the driving gears, the driven gear on the boring bar meshing therewith, and the gear for driving the feed mechanism, can all be housed in a single relatively compact casing. I have further found it of great advantage to apply power to the driving gears directly from prime movers, and specifically electric motors, mounted in pairs on each side of the driving gears, to which said motors are connected by differential mechanism. This insures that 'the maximum power of both motors of each pair will be applied to the driving gea'i'and also that the application will be perfectly balanced further cutting down vibration; My novel feeding mechanism is also in the highest degree efficacious and" combines very simply and compactly with thedriving means for the boring bar. By theuse of a single-rotating sleeve threaded upon the threaded extension of the boring bar and a shiftable pair of gears'in driving connection with" the boring bar through the same gear by which the'boring bar is rotated, Iam enabled to provide two advancing speeds for the boring barand a reverse or withdrawingoperation.

I'claim: I

1. A boring machine comprising "a rotatable operating member, a gear splined thereon, two pairs of prime movers P OSl-' tioned in pairs on the opposite sides of said member, and a'gear between each pair 'of said prime movers for joint operation thereby, said gears meshing with the first-named gear at diametrically-opposite points.

2. A boring machine comprising. a rotatable operating member, a gear splined thereon, two pairs of prime moverspositioned in pairs on the opposite sides of said member, and a gear between and differentially connected with each of said prime movers for joint operation thereby, said gears meshing with the'first-named gear to drive the operating member.

3. A boring machine comprising a rotatable operating member, a gear splined thereon, a pair of electric motors having their rotors in axial alinement, and a gearv between and differentially connected with each of SiLlCl rotors, said gear meshing with the first named gear to drive the operating member.

4. A bor1ng machine comprising a rotatable boring bar havinga gear encircling the same, two driving gears meshing with said first named gear at diametrically opposite points in a horizontal plane, a third gear meshing with said first'named gear, a shaft driven by said third gear, slidable change-speed gearing on the shaft, a,

threaded extension to the boring bar, a rotatable sleeve threaded thereon adapted to cooperate with said change-speed gearing, means for holding the sleeve stationary, and means to shift the first named change-speed said first named gear at diametrically oppo-' site points in a horizontal plane, a third gear meshing with said first named gear, said four gears being in a common vertical plane, a housing for all of said gears surrounding said boring bar, a shaft driven by said third gear, slidable change-speed gearing on the shaft, a threaded extension to the boring bar, a rotatable sleeve threaded thereon adapted to cooperate with said change-speed gearing, means for holding the sleeve stationary, and means to shift the first named change-speed gearing so as not to drive the threaded sleeve or to drive the same at two difierent speeds. V

6. A boring machine comprising a rotatable boring bar, a gear splined thereon, prime movers on the opposite sides of said bar, gears operated by said prime movers meshing with the first named gear at diametrically opposite points, a third gear also meshing with said first named gear, a rotatable sleeve having threaded engagement with said boring bar and connections for driving said rotatable sleeve from said third ear. g In testimony whereof I afiix my signature.

EDGAR A. DE FOREST. 

